You could use one additional "level" between the $40 and $80 droplets. 25GB is really not enough for me and what keeps me from upgrading from the standard droplet. 40GB with 2 cores might be a good idea.
Keith here from the Product team at DIgitalOcean. Have you tried attaching block storage to a Droplet to address that gap? You can learn more about Block Storage here https://www.digitalocean.com/products/storage/
Hope that helps,
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